An aqueous solution readily dissolves lead oxide, with formation of a strongly alkaline solution containing basic acetates (Acetum Plumbi or Saturni).
The chief pharmacopoeial salts are: (1) Plumbi oxidum (lead oxide), litharge.
It is not used internally, but from it is made Emplastrum Plumbi (diachylon plaster), which is an oleate of lead and is contained in emplastrum hydrargeri, emplastrum plumbi iodidi, emplastrum resinae, emplastrum saponis.
(2) Plumbi Acetas (sugar of lead), dose 1 to 5 grains.
From this salt are made the following preparations: (a) Pilula Plumbi cum Opio, the strength of the opium in it being i in 8, dose 2 to 4 grains; (b) Suppositoria Plumbi composita, containing lead acetate, opium and oil of theobroma, there being one grain of opium in each suppository; (c) Unguentum Plumbi Acetatis; (d) Liquor Plumbi Subacetatis Fortior, Goulard's extract, strength 24% of the subacetate; this again has a sub-preparation, the Liquor Plumbi Subacetatis Dilutis, called Goulard's water or Goulard's lotion, containing 1 part in 80 of the strong extract; (e) Glycerinum Plumbi Subacetatis, from which is made the Unguentum Glycerini Plumbi Subacetatis.
(3) Plumbi Carbonas, white lead, a mixture of the carbonate and the hydrate, a heavy white powder insoluble in water; it is not used internally, but from it is made Unguentum Plumbi Carbonatis, strength 1 in so parts of paraffin ointment.
(4) Plumbi Iodidium, a heavy bright yellow powder not used internally.
From it are made (a) Emplastrum Plumbi Iodidi, and (b) Unguentum Plumbi Iodidi.
Lead salts are applied as lotions in conditions where a sedative astringent effect is desired, as in weeping eczema; in many varieties of chronic ulceration; and as an injection for various inflammatory discharges from the vagina, ear and urethra, the Liquor Plumbi Subacetatis Dilutum being the one employed.
The chief use of the preparations of lead, however, is as an astringent in acute diarrhoea, particularly if ulceration be present, when it is usefully given in combination with opium in the form of the Pilula Plumbi cum Opio.